catamaran

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A boat with two parallel hulls or floats, especially a light sailboat with a mast mounted on a transverse frame joining the hulls.
• noun A raft of logs or floats lashed together and propelled by paddles or sails.

from The Century Dictionary.

• noun In lumbering, a small raft carrying a windlass and grapple, used to recover sunken logs.
• noun A kind of float or raft used by various peoples.
• noun Any craft with twin hulls, the inner faces of which are parallel to each other from stem to stern, and which is propelled either by sail or by steam. Sometimes shortened to cat.
• noun A quarrelsome woman; a vixen; a scold: a humorous or arbitrary use, with allusion to cat or catamount. See cat, 4.

from the GNU version of the Collaborative International Dictionary of English.

• noun A kind of raft or float, consisting of two or more logs or pieces of wood lashed together, and moved by paddles or sail; -- used as a surf boat and for other purposes on the coasts of the East and West Indies and South America. Modified forms are much used in the lumber regions of North America, and at life-saving stations.
• noun Any vessel with twin hulls, whether propelled by sails or by steam; esp., one of a class of double-hulled pleasure boats remarkable for speed.
• noun A kind of fire raft or torpedo bat.
• noun colloq. A quarrelsome woman; a scold.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A raft consisting of two or more logs tied together.
• noun A raft used on the St Lawrence River by lashing two ships together.
• noun A small rectangular raft used in dockyards to protect the hulls of large ships.
• noun A twin-hulled sailing yacht, especially one used for racing, the hulls being connected by a deck carrying the mast, rigging, cockpit and cabin.
• noun colloquial A quarrelsome woman; a scold.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a sailboat with two parallel hulls held together by single deck